The purpose of this work is to study translation of the RNA of representative members of an important group of viruses--the group whose genetic material is messenger RNA. We will use the in vitro protein synthesizing systems derived from wheat germ, from rabbit reticulocytes and sometimes from other sources. Among the RNAs to be studied are those from brome mosaic virus (BMV), Nodamura virus (NOV), southern bean mosaic virus (SBMV), tomato aspermy virus (TAV) and polio virus. By biochemical and other analyses, we want to determine what are the regulating factors involved in the translation of these RNAs in these systems and, where not already known, what information is encoded in the RNAs.